1 files changed, 80 insertions, 0 deletions
diff --git a/subprojects/lix-clang-tidy/HasPrefixSuffix.cc b/subprojects/lix-clang-tidy/HasPrefixSuffix.cc
new file mode 100644
index 000000000..e29b67e7c
--- /dev/null
+++ b/subprojects/lix-clang-tidy/HasPrefixSuffix.cc
@@ -0,0 +1,80 @@
+#include "HasPrefixSuffix.hh"
+#include <clang/AST/ASTTypeTraits.h>
+#include <clang/AST/Expr.h>
+#include <clang/AST/PrettyPrinter.h>
+#include <clang/AST/Type.h>
+#include <clang/ASTMatchers/ASTMatchers.h>
+#include <clang/Basic/Diagnostic.h>
+#include <clang/Frontend/FrontendAction.h>
+#include <clang/Frontend/FrontendPluginRegistry.h>
+#include <clang/Tooling/Transformer/SourceCode.h>
+#include <clang/Tooling/Transformer/SourceCodeBuilders.h>
+#include <iostream>
+
+namespace nix::clang_tidy {
+using namespace clang::ast_matchers;
+using namespace clang;
+
+void HasPrefixSuffixCheck::registerMatchers(ast_matchers::MatchFinder *Finder) {
+  Finder->addMatcher(
+      traverse(clang::TK_AsIs,
+               callExpr(callee(functionDecl(anyOf(hasName("hasPrefix"),
+                                                  hasName("hasSuffix")))
+                                   .bind("callee-decl")),
+                        optionally(hasArgument(
+                            0, cxxConstructExpr(
+                                   hasDeclaration(functionDecl(hasParameter(
+                                       0, parmVarDecl(hasType(
+                                              asString("const char *")))))))
+                                   .bind("implicit-cast"))))
+                   .bind("call")),
+      this);
+}
+
+void HasPrefixSuffixCheck::check(
+    const ast_matchers::MatchFinder::MatchResult &Result) {
+
+  const auto *CalleeDecl = Result.Nodes.getNodeAs<FunctionDecl>("callee-decl");
+  auto FuncName = std::string(CalleeDecl->getName());
+  std::string NewName;
+  if (FuncName == "hasPrefix") {
+    NewName = "starts_with";
+  } else if (FuncName == "hasSuffix") {
+    NewName = "ends_with";
+  } else {
+    llvm_unreachable("nix-has-prefix: invalid callee");
+  }
+
+  const auto *MatchedDecl = Result.Nodes.getNodeAs<CallExpr>("call");
+  const auto *ImplicitConvertArg =
+      Result.Nodes.getNodeAs<CXXConstructExpr>("implicit-cast");
+
+  const auto *Lhs = MatchedDecl->getArg(0);
+  const auto *Rhs = MatchedDecl->getArg(1);
+  auto Diag = diag(MatchedDecl->getExprLoc(), FuncName + " is deprecated");
+
+  std::string Text = "";
+
+  // Form possible cast to string_view, or nothing.
+  if (ImplicitConvertArg) {
+    Text = "std::string_view(";
+    Text.append(tooling::getText(*Lhs, *Result.Context));
+    Text.append(").");
+  } else {
+    Text.append(*tooling::buildAccess(*Lhs, *Result.Context));
+  }
+
+  // Call .starts_with.
+  Text.append(NewName);
+  Text.push_back('(');
+  Text.append(tooling::getText(*Rhs, *Result.Context));
+  Text.push_back(')');
+
+  Diag << FixItHint::CreateReplacement(MatchedDecl->getSourceRange(), Text);
+
+  // for (const auto *arg : MatchedDecl->arguments()) {
+  //   arg->dumpColor();
+  //   arg->getType().dump();
+  // }
+}
+}; // namespace nix::clang_tidy